What are Remote Sensing Applications (RSA)?
The term remote sensing most often refers to the collection of data by instruments carried aboard aircraft or satellites. However, remote sensing is also conducted through a land-based network of environmental sensing stations maintained by a variety of federal, state, and local agencies. Such remote sensing may track weather conditions, measurements of air and water conditions and quality, or other specialty data. Remote sensing applications are commonly used to survey, map, and monitor the resources and environment. Examples of images taken from remote sensing, organized by categories such as agriculture, human dimensions (e.g., environmental impact, population), land surface, and oceans, can be found at NASA's Visible Earth site, http://visibleearth.nasa.gov/.
There are several different types of remote sensing devices and applications. Many systems take photographs with cameras, recording reflected energy or images in the visible spectrum. Other systems record electromagnetic energy beyond the range of human sight, such as infrared radiation and microwaves. Still other systems employ a network of distributed electro-mechanical sensors and a central location for collecting, transforming, and summarizing the remote sensor data.
RSAs are varied and include archeological research, geologic investigations, mapmaking, meteorology, mining, volcanic activity, oceanography, and atmospheric and aquatic studies. Once data has been collected, verified, and stored, RSAs may be able to develop summaries and trends for the subject of analysis or topic of interest. For example, information about air quality for a metropolitan area could be collected and summarized by specialized RSAs. The analysis could provide information about compliance with federal air quality standards and the range of feasible transportation projects for that area. Another common use of RSA is photogrammetry or the science of taking measurements from photographs or other types of images to make physical maps, including topographic maps. The maps are generally developed from photographs taken by a special camera on an airplane.
Why is it useful?
RSA is valuable since it provides a means of collecting and analyzing environmental data at low cost and relative convenience. As a public involvement technique, RSA is useful to help the public understand the past and current environmental conditions in a particular study area or region. RSA also provides first-hand access to data that may be used to help educate the public, build confidence in other analytic methods, and foster a more active public role in the project or plan development.
Does it have special uses?
Because of the potential large-scale coverage of RSA techniques, the public is able to develop a firsthand appreciation of the macro and micro environmental features of a study area which would not have been possible until recently. Depending on the availability of quality data, a RSA could be useful in the various stages of a project, such as issue identification, development of options, and the selection of a preferred course of action.
Who participates? And how?
RSA are usually developed and managed by agencies. However, special interest groups may also use basic data from remote sensors to analyze and summarize their findings. Data sources are becoming increasingly available and without cost on public websites.
To conduct a remote sensor analysis, one needs access to the data and the conditions under which the data was collected. The data is then processed through specialized software, which has been developed and tested by experts. The results are verified, summarized, displayed, printed, and/or summarized for further interpretation and use. A variety of these collection and analysis activities are conducting between commercial firms and academic or non-profit organizations. For example, ESRI (a private firm engaged in GIS systems) maintains a Conservation Research Program that provides industry-academic-nonprofit collaboration on a variety of environmental and community remote sensing projects. These projects range from studies in conservation biology to environmental justice assessments (e.g. http://www.conservationgis.org/links/justice.html)
How do agencies use the output?
Products from RSAs are used in four primary ways:
- To educate the public about baseline environmental conditions and trends;
- To analyze and develop findings of community and environmental impacts of a proposed plan or project;
- To assist in displaying or conveying complex environmental information; and
- To obtain public comments or reactions.
What are the costs?
Because of the specialized nature of RSAs and the extent of the sensing network, the costs can vary significantly. Some data and information can be low cost because data and analyses are available through specialized Internet sites. If analyses or findings are not available, then RSAs may need to be developed to meet a specific project need. Sometimes this expertise is available within an agency. Consequently, the costs may vary from a few hundred dollars to several thousands, depending on the objectives of the RSA, the level of precision required, and the complexity and scope of the sensing data and subsequent analysis.
How is it used with other techniques?
RSAs complement other environmental data collection techniques. RSA is most effective when macroscale surveys of environmental data are required and the hardware and software for data collection, analysis, and reporting have been developed and verified. The data and findings can be used to assist or augment other public involvement techniques such as using reports and display materials to impart a baseline knowledge of environmental conditions, identifying issues/concerns, developing solution alternatives, selecting among alternatives, and communicating/displaying data, information, and knowledge.
What are the drawbacks?
RSA techniques are relatively straightforward, but the complexity of the process from sensing data to the communicating of findings is highly complex and may not be "transparent" to a non-specialist. This may create some issues of credibility and validity of the findings. Also, the cost of RSAs may be relatively high, although increased use of RSA during the past 20 to 30 years has helped to lower the user costs.
When is it used most effectively?
RSA are most effective when the technique is somewhat familiar to the public, e.g., weather sensing, the analysis process is relatively intuitive and straightforward, and the findings contribute to additional understanding and interpretation of the issues or discussion topics at hand.
For further information:
NASA's Observatorium offers education resources about remote sensing
http://observe.arc.nasa.gov/nasa/entries/entry_7.html
Integrated Global Observing Strategy is a major partnership of data providers and data users focused on atmospheric, oceanographic, and land-based observations
http://www.igospartners.org/
NASA's Visible Earth provides an excellent array of imagery grouped conveniently into categories such as agriculture, biosphere, human dimensions, and oceans
http://visibleearth.nasa.gov/
